The present invention relates to a method and a device for putting a U-section profile in place on a rim of a frame of a motor vehicle body or the like. The invention relates more particularly to the putting in place, on frames of motor vehicle doors or onto edges of openings of motor vehicle trunks, of weatherseals comprising such a profile forming a clamp, made from reinforced plastic material, and a sealing element adjoining this profile.
It is known that such seals usually comprise a U-section profile, comprising a metal reinforcement sheathed with a flexible material such as rubber or a plastic material, this profile being intended to be fixed by clamping onto a projecting edge or a projecting part of a motor vehicle body. This profile is associated with a flexible sealing element, for example tubular, intended to be compressed between two parts of the body, a door and its frame for example.
Numerous alternative embodiments of such profiles have been described in the prior art but, because the metal reinforcement of these profiles can be deformed and because the covering material can contract after the profile has been put in place on the associated body element, even when a profile in the form of a ring is used, the ends of which are connected to each other, a profile is usually used whose length is greater than that of the body element to be equipped, and it is put in position by compressing it slightly against this element. To this end, the ring profile is first fixed manually, using a flexible-headed mallet, at different points of the element of the body, between which it forms loops (so-called "looped" or "festooned" fitting). The profile is then put in place on the remainder of the body element, by continuously applying blows with a mallet between the initial fastening points, in order to cause the profile to clamp onto the body element over its entire length. Since the profile is to start with longer than the body element by a few tens of millimeters (generally 30 to 35 mm), the excess plastic material or rubber forming the clamp is thus forced into position by compression.
The longitudinal squeezing by approximately 10 to 15% of the sealing element adjoining the profile forming a clamp, which sealing element is generally made from a cellular material, makes it harder to deform than if it had not been subjected to the stress of putting the profile in place. It is then consequently difficult to close motor vehicle doors and trunks.
In addition to this disadvantage, this procedure for putting weatherseals in position on door frames or trunk openings makes use of an excess amount of raw material and is expensive in terms of personnel since a qualified worker takes several minutes to equip a door frame with the associated seal.
The object of the invention is to make good use of the appearance on the market of U-section profiles whose structure is such that their length is virtually invariable, under the stress of the contraction of the plastic material or during the fitting operations, both when in storage and after having been put in place on a body element, and it proposes to use, for this placing, a method which uses only a length of profile substantially equal to that of the body element to be equipped and which can be employed with the aid of an automated apparatus which does not entail the direct intervention of a worker.
To this end, the subject of the invention is a method for putting in place, on a projecting rim of a frame of a motor vehicle body, a U-section profile comprising a substantially non-extendable metal reinforcement sheathed with a resilient material, this reinforcement being substantially undeformable over time under the stress of the covering material, wherein a length of profile is used which is substantially equal to that of the body frame to be equipped, wherein a predetermined and possibly marked part of the profile is initially fastened in position at a predetermined, possibly marked, location of the rim of the body frame, and wherein, subsequently, with the aid of a vibrating flexible-headed mallet driven in an alternating striking movement, the profile is applied continuously against the rim of the body frame, starting from said predetermined location as far as a first end of the profile, and then, starting again from said predetermined location, as far as the other end of the profile.
It will be possible for the positioning of a predetermined part of the profile at a predetermined location of the body frame to be carried out manually or with the aid of the mallet with a vibrating head, or alternatively with the aid of a robot. In the case of a door frame, the predetermined location of the body element will preferably be situated in the top corner of the frame, contiguous to the corresponding central pillar of the body. In the case of a trunk opening, the predetermined location of the body frame will preferably be situated in either of the corners of the opening which are closest to the rear window of the vehicle.
The ends of the profile will preferably be joined together beforehand by means known from the prior art (by welding/adhesive bonding or welding/vulcanization of the plastic material and of the rubber, or using clips or the like) so that the profile forms a ring, as in the prior art technique of the "looped" fitting of the profile In the case of a door frame, the joining point of the two ends will be situated at the base of the door frame, preferably in the mid part of this base, or alternatively in the part of this frame arranged facing the central pillar. In the case of a trunk opening, the joining point of the two ends of the profile will be situated on that edge of the opening arranged at the rear of the vehicle, preferably in the mid part of this edge.
In such embodiments of the invention, the vibrating flexible-headed mallet can follow a continuous path in a same direction, from the initial fastening point of the profile at a predetermined location of the rim of the body frame as far as its starting point, following a continuous path over the entire length of the body element, and the mallet with a vibrating head can also follow a first path from the initial fastening point of the profile at a predetermined location of the rim of the body frame as far as any point whatsoever of this element, and then return to the initial fastening point in order to follow a second path in the reverse direction to the first as far as the point of the profile where it had stopped previously.
It will be possible for the initial putting of a part of the profile in place at a predetermined location of the rim of the body frame to be carried out manually or using a mallet with a vibrating head. It will also be possible for it to be effected by a different tool, in particular by a squeezing device carried by a head of a robot other than that activating the vibrating mallet, or by a second head carried by the robot activating the vibrating mallet.
It will be possible for the flexible head of the vibrating mallet to have a U shape so as to match the external shape of the profile forming the clamp and to facilitate its placing, at the same time guiding it along the body element to be equipped. This mallet will simply be fastened onto the rod of a vibrating, pneumatic tool-carrier of a type known per se, the nominal vibrating frequency of which is approximately 2,000 cycles per minute, at a compressed-air pressure of 6 bar. It will be possible for this frequency to be modified advantageously by varying the compressed-air supply pressure. The stroke of the vibrating mallet is approximately 30 mm. The pneumatic or electric, vibrating tool-carrier is of the type having vibrating blocks on which files or abrasive elements are frequently mounted.
In a preferred embodiment of the invention, the vibrating tool-carrier and the flexible-headed mallet integrally connected to the movable part of this tool-carrier will be carried by an arm of a robot and it will be possible for the method to be implemented in an entirely automated manner with the aid of this robot, programmed in a conventional manner. Here again, it will advantageously be possible to use as the robot robots commonly employed in automobile technology and the arm of which is provided, for example, with spot-welding tongs or with a paint gun, which elements need only be replaced by a flexible-headed mallet.
The flexible-headed mallet, or the structure carrying the latter, will preferably comprise at least one element for guiding the profile, for example a guide element with a U-shaped contour in which the arms of the U may be joined together at their upper part by a removable closing element such as a pin. It will be possible for this closing element to be activated by a control means such as a jack. Two similar guide elements, arranged in a same plane on either side of the rod of the mallet, for example symmetrically relative to the latter, will preferably be provided in order to ensure the guidance of the profile in all the positions of the mallet, a robot ensuring the passage of the profile from one guide element to the other, as well as the putting in place or withdrawal of the elements for closing the guide element, as is necessary.
It will be noted that whereas the plastic material and the reinforcement of the profile were compressed in the prior art of the looped fitting of the profile, with the present method in which the profile is continuously put in place on a rim of a frame of a body starting from a predetermined point with the aid of a vibrating tool which progresses along this body element, the profile is not subjected to any stress during its putting in place. A profile can therefore be used whose length is virtually identical to that of the body element to be equipped, a consequent saving being made on raw materials and there being a consequent lack of compression of the sealing element adjoining the U-profile, which subsequently facilitates the closing of the doors or of the trunk of the vehicles Moreover, the implementation of this method using a programmed robot ensures a better homogeneity of the fitting, and makes for an appreciable saving in terms of personnel.
It will also be noted that the use of a mallet with a vibrating head, possibly activated and controlled by a robot, makes it possible to employ profiles comprising a piece with a more closed U-section and therefore requiring greater placing forces than those for the profiles of the prior art, which ensures a better stability of these clamps on their support
Moreover, the implementation of the method according to the invention using a profile of a precise length, starting from a predetermined point of the body and from a marked location of the profile, makes it possible to use profiles in which the part forming a U-section clamp can have a variable opening depending on its length and adapted to the localized thicknesses of its support, at different locations of the door frame.
It will be possible to use any type of profile in which the length of the reinforcement does not vary over time, under the stress of the contraction of the coating material with which it is sheathed By way of example the profile forming the subject of the application for a French certificate of addition No. 2,626,054 will be mentioned, in other words a profile comprising a metal reinforcement with a U-shaped cross-section, sheathed with at least one plastic or elastomeric material, in which is embedded at least one virtually inextensible wire in the intermediate zone between the profile and the associated sealing element in the region of the center axis of the profile, said metal reinforcement resulting from the shaping into a U-shaped channel of a plane reinforcement comprising a succession of parallel bands of the same dimensions joined to the contiguous bands by two lateral spacers arranged symmetrically relative to the plane of symmetry of the U, to the exclusion of any central spacer arranged in the plane of symmetry.
The presence of the lateral spacers of such a reinforcement between the contiguous bands of the profile, combined with the presence of an inextensible wire embedded in the plastic material, ensures the undeformability of the profile over time. Such a profile, of a length of 3.3 meters, manufactured and marketed by the Applicant, thus preserves over time a constant length of within .+-.5 millimeters.
It is, moreover, not necessary, within the scope of the present invention, for the inextensible wire of the above profile to be situated between the profile and the sealing element, and it could equally well be arranged on the side of the profile opposite that on which the sealing member is situated. It is also possible to use two inextensible wires, arranged respectively along each of the arms of the U of the cross-section of the profile.
Other types of U-section profiles with a nonextendable reinforcement and of a substantially constant length over time, whether known from the prior art or not, could, of course, be used in the implementation of the invention.